pint.utils.pmtot

pint.utils.pmtot(model)

Compute and return the total proper motion from a model object

Calculates total proper motion from the parameters of the model, in either equatorial or ecliptic coordinates. Note that in both cases, pulsar timing codes define the proper motion in the longitude coordinate to be the the actual angular rate of change of position on the sky rather than the change in coordinate value, so PMRA = (d(RAJ)/dt)*cos(DECJ). This is different from the astrometry community where mu_alpha = d(alpha)/dt. Thus, we don’t need to include cos(DECJ) or cos(ELAT) in our calculation.

Parameters:

model (pint.models.timing_model.TimingModel) –

Returns:

pmtot – Returns total proper motion with units of u.mas/u.yr

Return type:

astropy.units.Quantity

Raises:

AttributeError – If no Astrometry component is found in the model